<?php
/**
 * Created by function.php.
 * User: tqj
 * Date: 2017-05-29
 * Time: 11:28
 */

/*
 * 字符串截取函数
 * 开启mbstring使用
 * */
function msubstr($str, $start = 0, $length, $charset = "utf-8", $suffix = true)
{
    if(function_exists("mb_substr")) {
        if($suffix)
            return mb_substr($str, $start, $length, $charset) . "...";
        else
            return mb_substr($str, $start, $length, $charset);
    } elseif(function_exists('iconv_substr')) {
        if($suffix)
            return iconv_substr($str, $start, $length, $charset) . "...";
        else
            return iconv_substr($str, $start, $length, $charset);
    }
    $re['utf-8'] = "/[x01-x7f]|[xc2-xdf][x80-xbf]|[xe0-xef][x80-xbf]{2}|[xf0-xff][x80-xbf]{3}/";
    $re['gb2312'] = "/[x01-x7f]|[xb0-xf7][xa0-xfe]/";
    $re['gbk'] = "/[x01-x7f]|[x81-xfe][x40-xfe]/";
    $re['big5'] = "/[x01-x7f]|[x81-xfe]([x40-x7e]|xa1-xfe])/";
    preg_match_all($re[$charset], $str, $match);
    $slice = join("", array_slice($match[0], $start, $length));
    if($suffix) return $slice . "…";
    return $slice;
}

/*
 *工厂方法
 *传递过来一个模型类的类名
 *放返回给类一个实例对象，而且，保证其单例。
 * 
 */

 function instanceClass($objname){
    if($objname){
         echo "hello2";
        static  $insclass=array();
        if( !isset($insclass[$objname]) || !($insclass[$objname] instanceof $objname )){
            $insclass[$objname]=new $objname();
        }
        return $insclass[$objname];
    }
     echo "hello1";
    return false;
 }


